Wasn't that a good one about the president promising an executive order on immigration -- only he discovered the time wasn't quite right, what with an election coming on, so he pivoted to the Islamic State, which he is promising to degrade and destroy in two or three years, only ... ?

The "onlys" tend to get you when they accumulate too fast: attempted cover for broken promises and stalled undertakings. This might be another way of saying, does Barack Obama, hours after kicking the immigration can down the road, really expect the world to take with profound seriousness his renewal of the terror war he denounced when others were waging it?

Obama's shifts of viewpoint and rhetoric have become as commonplace as fall-weather chitchat. Say, Ned, reckon it's about to cool down some? Reckon there'll be boots on the ground by Thanksgiving?

A president without firm policy commitments, and a certain firmness of character in pursuing those commitments, starts, in time, to lose the public's attention. We will see in time whether the foulness of the Islamic State keeps Barack Obama awake long enough to cleanse this stench from the air. It might. It should. The sadness of the moment proceeds not from beheadings and crucifixions alone but from the fear of ineptitude and inconstancy in high places and their capacity for sidetracking foreign policy work -- war work -- that badly needs doing.

Can Obama see the job through? Has he the vision? Has he the guts? It is awful to have to ask such questions, but they are the questions America's enemies, as well as its dwindling supply of friends and clients, are asking. What do you suppose -- say -- must be the odds Vladimir Putin is giving privately on our president's endurance? What odds would he have laid, correspondingly, on George W. Bush's?

It is no idle question. The 44th president, back when he was a mere U.S. senator from Illinois, fell to excoriating the 43rd president for the same staunchness of judgment he himself would now like credited to his own account. If back then you didn't like Bush or his policies, that was OK. You knew this at least: No. 43, believing firmly in what he was trying to do, kept his eye fixed on those ends.

The '08 election was largely a referendum on the Bush credo and the Bush practice, considered together. The political left had had it with that non-bashful, ultra-provocative approach to the conduct of affairs. Sen. Barack Obama ran as the un-Bush, the candidate least likely to make foreign mobs and heads of government angry with his policies and verbal style. With his predecessor's policies and style, as little as it was noticed at the time, went a consistency that shored up the points he wished to make. We knew where he stood; we understood what he would do.

No. 44 promises to make miserable the lives of beheaders and similar riffraff. We are bound, in common sense, to hope he does, and to support all reasonable efforts to this end. We are bound at the same time to acknowledge how much harder is the task on account of what America did in 2008.

What we did then can be shown in two parts:

We raised a great cry for relief from the job we had handed, with a very great cry indeed, to George W. Bush -- the job of mashing and mauling America's merciless enemies. If we now see the Iraq war as unwise and destabilizing, that is hindsight wisdom: neither wrong nor an object for present admiration.

We accepted at face value the self-back-patting of an untried, untested presidential candidate with a messianic streak ill-suited to the small abilities we now recognize in him.

Well, here we are, and here he is, too: the only president we've got, charged with a mission he plainly doesn't want, but which, for the country's good, and the world's, can't be dodged.

He deserves the chance to make good. We deserve the job of making sure he does just that.